The present invention relates, in general, to railway braking systems and, more particularly, the present invention relates to a modification in the service accelerated release valve gasket to help eliminate emergency reservoir (ER) to brake pipe (BP) gasket leakage.
Braking systems on railway vehicles, or with any type of moving vehicle, is an extremely important component. Any problems that occur in a braking system are deemed to be serious and attempts to eliminate or improve any such problems are given the highest priority.
Since the introduction of pneumatic braking systems more than 125 years ago, such railway braking systems have been constantly modified and revised to improve braking performance. Some of the improvements may have seemed minor, however, any improvement that can make a braking system more reliable and, thus, safer is never looked upon as minor.
New freight brake control valves, empty/load equipment, single sided brake pipe brackets, along with single car testing equipment, composition brake shoes and a multitude of other improvements have been introduced through the years. These new members have, in turn, been modified and altered in a constant effort to improve the braking systems. Whenever a problem has cropped up in any facet of the braking system on railway vehicles efforts throughout the railroad industry have been undertaken almost immediately to alleviate the problem, even if the problem appeared to be a minor one because, as mentioned previously, no problem is minor with respect to braking.
Some problems have sporadically been encountered during periods under high pressure differential conditions. When a high pressure differential condition exists between ER and BP, with ER being the higher pressure, distortion of a gasket can occur in the service portion of a brake control valve. Depending on the magnitude of the distortion, the gasket""s ability to seal can be affected which can, therefore, affect emergency braking.
Therefore, the present invention provides a gasket for use in a service portion of a brake control valve in a railway braking system. The gasket comprises an elastomeric composition having a predetermined shape which includes a first surface and a opposed planar second surface. There is a first at least one bead like projection formed on the first surface of the gasket closely adjacent an outer periphery of the first surface and extending around the outer periphery of the first surface. Such bead like projection assists in sealing the gasket to a body of such service portion of such brake control valve.
There is a first aperture disposed in the gasket having a first predetermined location and a first predetermined diameter. The first aperture is in fluid communication with Emergency Reservoir and for engagement with a projection disposed on a filling piece of such service portion of such brake control valve. A second at least one bead like projection is formed on the first surface around an outer circumference of the first aperture for sealing the gasket to such body of such service portion of such brake control valve.
A brass insert is molded into the elastomeric composition and disposed in a second predetermined location. The brass insert has a second aperture, which has a second predetermined diameter, formed therein. The second aperture is in fluid communication with an auxiliary reservoir of such railway braking system. A third at least one bead like projection is formed around the second aperture on the first surface in a generally U-shape with an open part of the U contacting a portion of the first at least one bead like projection. Again this bead like projection is for sealing the gasket with such body of such service portion of such brake control valve.
A third aperture is formed in the gasket in a third predetermined location and has a third predetermined diameter. There is a fourth at least one bead like projection that is formed on the first surface between the second at least one bead like projection and a portion of the first at least one bead like projection. Again such bead like projection aid in the sealing of the gasket with such body of such service portion of such brake control valve. A fifth at least one bead like projection is formed on the first surface between the second at least one bead like projection and a portion of the first at least one bead like projection. The fifth at least one bead like projection being axially opposed from the fourth at least one bead like projection. A sixth at least one bead like projection is formed on the first surface between the second at least one bead like projection and a portion of the first at least one bead like projection for sealing the gasket with such body of such service portion of such brake control valve. The sixth at least one bead like projection being substantially transverse to the fourth and the fifth at least one bead like projection.
A brass insert having a first predetermined configuration is molded into the elastomeric composition of the gasket. The brass insert is disposed in a lower quadrant of the first surface of the gasket and has a fourth aperture formed therein. The fourth aperture is in fluid communication with a brake pipe in such body of such service portion of such brake control valve. The fourth aperture has a second predetermined configuration.
There is at least one bead like projection formed on the radially opposed second surface of the gasket and positioned such that the at least one bead like projection formed on the radially opposed second surface of the gasket correspond to similar positions, but radially opposed, for each of the first, the second, the third, the fourth, the fifth and the sixth of the at least one bead like projection formed on the first surface of the gasket. The at least one bead like projection formed on the radially opposed second surface of the gasket is for sealing contact with such filling piece of such service portion of such brake control valve. A dowel projection having a third predetermined configuration is disposed on the radially opposed second surface of the gasket for engagement with a cavity in such filling piece of such service portion of such brake control valve.
It is, therefore, one of the primary objects of the present invention to provide a gasket which will resist leakage under high pressure differential conditions.
It is another object of the present invention to provide a gasket which will possess greater rigidity so the gasket will retain its position.
It is still another object of the present invention to provide a gasket with brass inserts which will provide the strength necessary to reduce or prevent incidence of leakage.
It is yet another object of the present invention to provide a gasket which will not only have the rigidity necessary to resist leakage under periods of high differential pressure but will maintain good sealing properties.
In addition to the various objects and advantages of the present invention which have been described in some specific detail above, various additional objects and advantages of the present invention will become much more readily apparent to those persons who are particularly skilled in the relevant railroad braking systems from the following more detailed description of such invention, particularly, when such detailed description is taken in conjunction with the attached drawing Figures and with the appended claims.